Recording and reproducing apparatus



L- J BARBARA ETAL RECORDING AND REPRODUCING APPARATUS 2 Sheets-Sheet 1 Filed Aug. 5, 1946 INVENTORS LOU/S BIKE/IRA MARVIN M, KLE/N BYBERA/Akfl HOW/4RD.

ATTORNEY Get. 17, 1950 J, BARBARA ETAL' 2,525,995

RECORDING AND REPRODUCING APPARATUS Filed Aug. 3, 1946 2 Sheets-Sheet 2 INVE TOR LOU/SJ. Amy/17 MARVIN M. AL'f/A/ BY EEK/WIRE //0m4,m.

ATTQRNEY Patented Oct. 17, 1950 RECORDING AND REPRODUCING APPARATUS Louis J. Barbara, Woodside, and Marvin M. Klein, Jackson Heights, N. Y., and Bernard Howard, North Arlington, N. J.

Application August 3, 1946, Serial No. 688,355

6 Claims. 1

Our invention is an improvement in recording and reproducing apparatus, in which a wire is magnetized by means of an electro-magnetic coil through which current is caused to fluctuate under the control of the human voice or other sounds; and which is subsequently caused to move in inductive relation to a coil to generate therein an electric current having corresponding fluctuations for the reproducing operation. The improvement relates more particularly to mechanism for controlling the means by which the wire is operated.

The wire employed for the purpose is usually of steel in suflicient length but of very small di-- ameter. It is actuated by means of a pair of reels; being unwound from one and wound up on the other, the reels being rotated so as to pull the wire over guide pulleys between two of which the coil used to magnetize the wire for recording and to be in turn influenced by the wire for reproducing is mounted. The movement of the reels must be carefully regulated to prevent breaking of the wire, and for this purpose it is desirable to actuate the reels not at a fixed number of revolutions per minute, but to vary gradually the rate of angular speed thereof so that the peripheral speed of the wire on both reels is the same; and the tension thereof is prevented from rising too high. Otherwise the wire is apt to be ruptured and the recording and the reproducing have to be stopped till proper working conditions are reestablished.

The most important object of the invention is to provide means for rotating the reels in either direction, so arranged that the wire can be unwound from one reel and wound up on the other; and then unwound from the latter and rewound on the first whenever required, and to regulate the revolution of the reels so that the wire can be actuated in the manner above stated.

A- further object of the invention is to provide means for rotating the reels which will act as above described, said means being arranged so that after the wire is unwound from one reel it can be rewound thereon much more rapidly. Reproduction is thus greatly facilitated.

Another object of the invention is to provide means for revolving the reels at the required speed from the same driving shaft by suitable connections which are automatically completed for each direction of rotation as soon as the shaft starts turning.

The nature and advantages of the invention are fully set forth in the ensuing description, taken in connection with the drawings; but in practice many alterations may be made in the construction illustrated herein without deviating from the principle underlying the invention.

On the drawings,

Figure 1 is a front view of a magnetic recording and reproducing apparatus containing mechanism according to this invention;

Figure 2 is a partial section thereof showing a form of spreader for the wire; and

Figure 3 is a vertical section on the line 33 of Figure 1.

The apparatus comprises a front plate I and a back plate 2 connected by cross bars or bolts 3. These parts make up a supporting framework for the apparatus and on said framework is rotatably mounted a pair of reels 4 and 5 at the outer face of the plate I. Suitable bearings in the plates l and 2 carry rotatable shafts 6 pro-- jecting through the plate I and to the forward ends of these shafts the reels are secured and keyed in any suitable way. The reels are turned by a belt 7 that engages the coils of wire W on the reels, and this belt always runs in contact with the layers of wire on both reels, so that the peripheral speed of the wire on one reel is always the same as on the other. This belt is driven by a shaft 8 connected to a motor with a reversing switch (not shown) so that the shaft can be revolved in either directions. This shaft has threads 9 and carries a disc of some weight to form an inertia member iii. This member has a central opening therein to receive the threads 9. At each side of the member Ill and affixed thereto in any approved manner, are clutch members ll, that cooperate with similar clutch members [2, cpposing them face to face. The members i2 have rigid hubs [3, through which the shaft 8 passes, and these clutch members 12 are loosely mount-- ed on the shaft 8. On the adjacent faces of each. pair of members H and I2 are rings or layers I i.

of rubber or some other frictional material.

Each of the hubs 13 of the clutch members l2: has a circumferential groove therein, and over each pulley so formed passes a belt 15. The belts I5 run to pulleys l6 and ll, of unequal size, on a shaft H3 in the framework under and parallel with the shaft 8. These pulleys l6 and I! are rigid with the shaft l8 and lie between the plates I and 2. The shaft l8 projects through the front plate, and adjacent the latter it carries rigidly secured thereto the driving pulley IQ for the belt 1.

Shafts 8 and it are carried by the supporting framework in substantially central position, and the reels 4 and 5 are at each side of these two.

3 shafts. The Wire strand shown at W passes from one reel to the other over several guide pulleys on the outer face of the front plate Above the pulley i9 is another flanged pulley for the belt i, which is of rubber or some other substance having a frictional surface. The reels 4 and 5 are close enough together for the belt to pass between them and make contact with the layers of wire on both reels at once; and as one reel fills and the other is unwound, leaving thinner layer of wire thereon, the belt can swing sideways away from the fuller reel to the extent required to maintain contact with substantially even pressure on both reels. To this end the pulley 28 revolves on a journal 2i attached to an arm 22 which is pivotally secured in the forked end of a lever 23 by a pin or screw 24; so that the upper pulley 25} can swing from side to side. The lever 23 is pivoted at 25 on the inner face of the plate 2; and is engaged at the other end by a I sping 26, anchored to the inside face of the plate I. A large hole 2? in the plate allows space for the play of the journal i.

If the wire is wound on the reel t, for example, when recording is to be accomplished, it passes first over a guide pulley 28 at the left of the reel l, then down under a similar pulley below the reel l, over to a guide pulley 28 under the reel 5, then to a guide pulley 28 above and to the right of reel 5 to the last-named reel. pulleys 28 are all mounted on shafts 29. The bars or screw bolts Si carry spacer sleeves Between, the two lower pulleys 28 is an electromagnetic coil With the reel t filled the belt l is set to en gage with its outer surface against the wire thereon; and on the opposite side with its outer surface pressing at first against the core of the reel 5, which receives the wire. The circuit of the motor is then closed and the inertia mem ber IE is at once moved by threads 9 on the shaft 8 so that it will engage and turn the clutch member it which is connected to the pulley it. With the motor rotating, this member IE will revolve the pulley i t; and the pulley 59 will cause the belt '5 to make the reel unwind and the reel 5 to wind, up the wire thereon. As the layers of wire on the reel 5 increase, the lateral pressure of the thickening wire thereon against the belt pushes the pulley 26 more and more to the left to keep the belt in efficient contact with both reels. The peripheral speed of the wire on one reel is kept equal to the peripheral speed of the wire on the other; because this speed at both reels is fixed and determined by the movement of s.

the belt i even though speed of revolution of the two reels may vary. Hence, the tension of the wire W as it is drawn from one reel to the other is safely controlled.

During this motion the wire passes through or by the electric magnetic coil indicated at 3| and is magnetized to a different degree at every point in its length by pulsating current in this coil, the current being controlled by a microphone or the like modulated by the sounds which are to be recorded. The operation for recording and reproducing is the same as set forth in our companion application for patent on improvements in Magnetic Recorders and Reproducing Apparatus, Serial No. 688,354 filed of even date herewith.

When reproducing is desired, the wire is moved in the opposite direction to be rewound up on the reel 4 at the left. In this instance the arm 22 and pulley 25 are now farther over to the left, but the belt 1 makes contact with the layers of The wire on the two reels as before. The motor is now operated in a reverse direction so that the member If! moves the other or left-hand pair of clutch members [I and i2 into engagement. Now the larger pulley Ill and the shaft l8 receive motion from the shaft 8, and the shaft it rotates the belt 7 in the reverse direction to draw the wire back on the reel 4 from which it was unwound in the first place.

A spreader of conventional design can be iricluded to wind the wire in smooth, even layers on the reels. For this purpose, the shaft 6 of the reel 5, for instance, is shown as having threads 32, and just below this shaft is a bracket 33, fastened to the inner face of the plate 5 by screws or the like 34. At the upper side of this bracket is an arm 35 mounted on a pivot post 35 at one end. On the top of the bracket is a gear 3'], rotating on a journal 38 fixed to the bracket and meshing with the worm threads 32. This gear is integral on itsupper face with a pinion 3i: which rotates a second gear ii] just above and overlapping the gear 3?. The latter has a shaft in the bracket and is affixed to the shaft 38' and this shaft carries on top of the gear ill a cam ii. The swinging arm runs from the pivot post 36 above the worm threads 32, (being broken away to show these threads) and over the gears 3? and 4t and the cam 45. The construction is illustrated in Figure 2, but the gears appear in dotted outline only for the sake of clearness. Adjacent the cam ti the arm has downward extending ribs 42 at both side edges. The arm 35 has a stud 43 that engages a grooved collar 3 on the shaft 38 of the pulley 25 that is just a little higher and to the right of the reel 5. The shaft 29 of this pulley is reciprocable in its bearings supported by the plates I and 2, and as the mechanism is operated, the rotation of the shaft of the reel 5 causes the cam 4i between the ribs 42 to swing the arm 35 back and forth to keep the pulley 28 moving between the two flanges of the reel 5 to spread the wire turns evenly in each layer as required. The cam All and the inner faces of the ribs 42 are properly formed to operate as required. A single rib 42 can be employed with a spring stretched between the arm 35 and a convenient fixed point to keep the arm in contact with the cam as the latter rotates.

A similar spreader will be used in connection with the other reel and the other upper guide pulley 28 to move the latter so as to make the layers of wire smooth and even on the reel 4, when the wire is rewound thereon; but this second spreader is not included in the drawings, being omitted for the sake of convenience. The two spreaders are not part of this invention, but they operate together to facilitate the winding and unwinding of the two reels and 5.

The wire W can be of metal, or of paper or some other material carrying particles of magnetic metal; and the mechanism described can be employed for devices other than magnetic recorders and reproducers but requiring the same mode of operation.

This construction is well adapted to serve the purpose, is simple and inexpensive to produce, and easy and certain in operation. All risk of putting too much tension on the wire and breaking the wire is eliminated.

Likewise a clutch differing from the inertia element l0 and members H and i2 in structure and operation could be utilized to impart motion in opposite directions to the shaft 18 when the motor is run to rotate in one direction or the other the drive shaft 8.

Having described our invention, what we claim is:

1. Mechanism for recording and reproducing apparatus comprising a pair of reels to carry a strand of wire to be transferred from one reel to the other, a belt making contact with the wire on both reels to impart motion thereto, means for driving said belt and means for permitting the belt to shift laterally; the means for driving said belt comprising a shaft having threads, an inertia member thereon engaged by said threads, clutch members and pulleys rigid therewith on said shaft to be alternatively engaged b said inertia member, a second shaft and pulleys affixed to the second shaft, each to be driven by one of said clutch members. 7 r

2. Mechanism for recording and reproducing apparatus comprisin a supporting framework and having a pair of reels rotatably mounted thereon to carry a strand of wire to be transferrd from one reel to the other, a belt making contact with the wire on both reels to impart motion thereto, a shiftable pulley for carrying said belt, and another pulley for driving said belt, a shaft in said framework to support the last named pulley, another shaft carried 'by said framework having a threaded portion with an inertia member thereon, a clutch member at each side of said member, a pulley carried by each clutch member, and means for connecting said pulleys alternatively to said shaft supporting the driving pulley. i

3. Mechanism for recording and reproducing apparatus comprising a supporting framework, a pair of reels on the framework to carry a strand of wire to be moved from one reel to the other, a belt making contact with the Wire on both reels to impart motion thereto, pulleys for said belt,

, 6 V belt making contact with the Wire on both reels, a pulley for operating the belt, a second pulley for the belt, means for shifting the secondpulley to move the belt sidewise, a shaft on which the operating pulley is mounted, fixed pulleys on said shaft, another shaft parallel to th first shaft, a

pair of pulleys loosely mounted on the other shaft, and connected to the pulleys on the first shaft,

and means for rotating the other shaft in reverse direction.

5. Mechanism for recording and reproducing apparatus comprising a pair of reels to carry a strand of wire to be transferred from one to the other, a supporting framework, a power shaft mounted in said framework and having threads thereon, an inertia member on the shaft engaged with said threads, clutch members "loosely to the other, a belt making contact with the wire on both reels to impartmotion thereto, means for driving said belt and means for permitting the belt to shift laterally; the means for driving said belt comprising a shaft, clutch members and FOREIGN PATENTS Number Country Date 270,050 Great Britain May 5, 1927 614,821 France Dec. 23, 1926 706,197

pulleys rigid therewith on said shaft to be alternativel operated by said shaft, a second shaft and pulleys affixed to the second shaft, each to be driven by one of said clutch members.

LOUIS J. BARBARA. MARVIN M. KLEIN. V BERNARD HOWARD.

REFERENCES CITED The following references are of record in the file of this patent:

France June 19, 1931 

